A reader asks: "Can someone comment on the legality of using my brother's old Snow Leopard DVD to install OS X? My brother has Lion, so why can't he choose to give it to me? It doesn't violate Apple's 1 license per 1 computer policy."

installing a legally purchased copy of Mac OS X on your Hackintosh does not require that you violate copyright

Copyright is a law that allows authors to restrict distribution (and in software, use) of a work. An author grants you a right by way of a license. Although EULAs haven't been in court as much as many people think, I believe (and I've studied this in detail) that a EULA is best characterized as a contract where one party grants a license in exchange for money and other aspects to an agreement.

The consequence of this is that if the contract is void, no license is granted. EULAs typically also provide that the license will not be granted, or will be revoked, in response to a breach. That, in turn, makes any duplication - including copying code to a hard drive or into memory as part of execution - to be an act of copyright infringement.

It may be impossible to enforce, but it's certainly not clear to me that installing OS X to a non-Apple branded machine would not give rise to copyright infringment (in addition to breach of contract and DMCA specific remedies.)

The real issues here (IMO) are found in competition law. Apple have so far avoided being subject to that, but success can give rise to a legal response.

In reference to your copying argument, I think there is reason to claim fair use. If I own a book, I am allowed under fair use to make a copy of it for personal use. Maybe I want to annotate the copy. Maybe I don't want to risk the original getting wet in the tub. For books, the original and the copies are considered a single entity. If you sell the book, you either need to destroy the copies or give them with the book. Going back to computers, it is perfectly legal to make backup copies of your installation media. Media don't last forever, and copies of the original makes sense. While I am sure Apple would argue against this reasoning, outside of computers this type of thing is ordinary. Why do you think they have photocopiers in most libraries?

if the contract is void, no license is granted...That, in turn, makes any duplication - including copying code to a hard drive or into memory as part of execution - to be an act of copyright infringement.

In reference to your copying argument, I think there is reason to claim fair use...